Compositions comprising magnesium oxide and elastomeric isocyanate-modified linear polyesters



ited States OXIDE AND ELASTOMERIC ISQCYA- NATEMODHIED LINEAR POLYESTERSWilliam L. Bruce, Norrkoping, Sweden, assignor, by mesne assignments, toThe Goodyear Tire & Rubber Company, a corporation of Ohio No Drawing.Application January 27, 1953, Serial No. 333,611

(Claims. (Cl. 260--40) This invention relates to synthetic elastomericpolymers. More particularly it relates to elastomericdiisocyanatearnodified linear polyesters and polyesteramides. Still moreparticularly it relates to synthetic elastomers prepared fromdiisocyanate-modified linear polyesters and polyesteramides in which theamount of isocyanate required to efiect a cross-linking or cure of themodified polyester or polyesteramide is held to a minimum. The syntheticelastomeric polymers to which this invention relates are those describedin co-pending applications Serial Numbers 187,696, filed September 29,1950, now United States Patent 2,625,532; 305,914, filed August 22,1952; 307,900, filed September 4, 1952, and 312,161, filed September 29,1952, now United States Patent 2,625,535. These materials, which aredescribed in detail below, will hereinafter be referred to aselastomeric diisocyanate-modified linear polyesters.

As described in the co-pending applications referred to above, theelastomeric diisocyanate-modified linear polyesters are formed byreacting the polyesters and polyesteramides of specified molecularweight and chemical structure with controlled amounts of certainspecific diisocyanates. The reaction product so formed is an uncuredmaterial similar to uuvulcanized natural rubber in its physicalcharacteristics. After compounding, the uncured material is mixed withan additional controlled amount of polyisocyanate which acts as across-linking or curing agent for the modified, linear polyester.

It is with this second incremental addition of polyisocyanate that thisinvention is concerned. It is an object of the invention to provide ameans for reducing the amount of polyisocyanate required to effect asatisfactory cure of the elastomeric diisocyanate-modified polyesters.lt is a further object of this invention to improve the cured physicalproperties of the synthetic elastomers while at the same time reducingthe amount of polyisocyanate required to effect such cure. Anotherobject of this invention is to reduce the cost of the cured elastomerwithout reducing its quality. Other objects will appear as thedescription proceeds.

atent 0 the amount of polyisocyanate required to effect a satisfactorycure, without impairing the physical properties of the cured material,by the use of magnesium oxide.

By the use of magnesium oxide in the compounding of the uncured polymer,it is possible to reduce the amount of polyisocyanate required to effecta cure so that the total number of isocyanate equivalents in the curablemixture is a minimum of from 2.40 to 2.80 equivalents per mol ofpolyester or polyesteramide as compared with a minimum of 2.80 to 3.20equivalents without magnesium oxide. The amount of magnesium oxide usedis not critical; as little as 0.50 part or as much as 20 parts by weightper 100 parts of the synthetic elastomer may be used. A preferred rangeis from 1 to 10 parts by weight per 100 parts of polymer. Amounts inexcess of 20 parts may be used, but no increased beneficial eliect isrealized by the use of such amounts of magnesium oxide.

While each class of elastomeric diisocyanate-modified linear polyestersto which this invention is applicable has been fully described in theapplications referred to above, the general chemical reactions involvedin their preparation may be typically represented by the followingillustrations in which R, R, and R" denote divalent organic radicals.

PREPARATION OF POLYESTER (1) II I! unto-R 011) MHO-O-IV-C-OH) 0 H(OR-O(i-R( J),,-OH+(2n-1)H;O in which n is a positive whole number denotingthe degree of polymerization of the polyester formed.

PREPARATION OF POLYESTERAMIDE O 0 n(HOR-NH2) 7L(HOi IR-( I-OH) H O OH(ORIil(i7R-Hl)fl--OH+(2n1)HzO PREPARATION OF DIISOCYANATE-MODIFIED (3)POLYESTER O O (Ho o1 ester-ii-1 r- I -h-o 01 ester-h m-on+mo 0 s inwhich 101 is a positive whole number denoting the number of segments inthe diisocyanate-motlified, chainextended polymer.

PREPARATION OF DIISOCYANATE-MODIFIED POLYESTERAMIDE It has been statedin the co-pending applications referred to above that, in order todevelop a satisfactory cure, it is necessary to add sufiicientpolyisocyanate to in which in is a positive whole number denoting thethe uncured modified polyester or polyesteramide to bring the totalnumber of isocyanate equivalents present in the curable mixture to aminimum of from 2.80 to 3.20 equivalents per mol of polyester orpolyesteramide. It has now been discovered that it is possible to reducenumber of segments in the diisocyanate-modified, chainextended polymer.

in which R? and R represent divalent organic radicals andm represents apositive whole number denoting the number of segments in the modifiedchain-extended intel-polymer.

Equations 3, 4, 5, 6 and 7 represent the reactions which may take placein forming the uncured elastomeric polymers according to the limitationsas to acid number, hydroxyl number, amino groups, bifunctionaladditives, and amount of particular diisocyanate used in theirpreparation, described in the co-pending applications referred to aboye.

The curingor cross-linking of the uncured polymers takes place as theresult of reaction between the NCO groups in the curing agent and thereactive hydrogens in certain groups present in the chain of theextended polymer and certain terminal groups at the ends of thechainextended units. The terminal groups include, of course, hydroxyl,carboxyl, and amino radicals. The groups along the chain include thegroups formed by reaction between an -NCO group and a carboxyl,hydroxyl, or amino group, and may be represented as a substituted amidelinkage O ll-LL) a carbamic radical and a ureylene radical O t-fI-JLL'P)respectively. Each of these groupings has at least one active hydrogenavailable for reaction with the NCO group of the polyisocyanate used toeifect a cure.

The elastomeric diisocyanate-modified linear polyesters described in theco-pending applications referred to above may be grouped in four generalclasses.

First, the reaction product of (1) a polyester or polyesteramideprepared from at least one dibasic carboxylic acid and at least oneglycol, and/ or at least one amino alcohol, and/ or at least onediamine; the number of hydrogen-bearing amino groups being present in anamount not to exceed 7.5% of the total hydroxyl and hydrogenbearingamino groups present, the polyester or polyesteramide having a hydroxylnumber from 40 to 100 (a preferred range is from 50 to 60) and an acidnumber from to 7; and (2) at least one diisocyanate selected from thegroup consisting of 4,4-diphenyl diisocyanate; 4,4-diphenylene methanediisocyanate;.dianisidine diisocyanate; 4,4'-to'lidine diisocyanate;1,5-naphthalene diisocyanate; 4,4'-diphenyl ether diisocyanate; andp-phenylene diisocyanate, the diisocyanate being used in an amountranging from 0.70 to 0.99 (a preferred range is from 0.90 to 0.99) molper mol of polyester or polyesteramide.

Second, the reaction product of (1) a polyester or polyesteramideprepared from at least one dibasic carboxylic acid, and at least oneglycol, and/or at least one amino alcohol and/or at least one diamine,the number of hydrogen-bearing amino groups present being in an amountnot to exceed 30% of the total hydroxyl and hydrogenbearing amino groupspresent, the polyester or polyesteramide having a hydroxyl number from30 to 140 (a preferred range is from 50 to 60) and an acid number from 0to 12; and (2) at least one tolylene diisocyanate used in an amountranging from 0.85 to 1.10 (a preferred range is from 0.90 to 1.00) molper mol of polyester or polyesteramide.

Third, the reaction product resulting from the reaction of a mixturecomprising (1) a polyester prepared from bifunctiona'l ingredientsincluding at least one dibasic carboxylic acid containing at least threecarbon atoms, and at least one glycol, said polyester having a hydroxylnumber from 30 to 140 a preferred range is from 50 to 60) and an acidnumber from 0 to 12; (2) at least one bifunctional additive selectedfrom the group consisting of diamines, amino alcohols, dicarboxylicacids, amino carboxylic acids, hydroxy carboxylic acids and the ureas,guanidines and thioureas containing a primary amino group, saidbifunctional additive being used in an amount such that the total numberof -NH2 and -COOH equivalents present in said bifunctional reactantshall be from 0.06 to 0.24 equivalent per mol of polyester, and (3) atleast one tolylene diisocyanate used in an amount equal to the sum offrom 0.85 mol to 1.10 (a preferred range is from 0.90 to 1.00) mol ofdiisocyanate per mol of polyester plus the molar amount of diisocyanateequivalent to the mols of said bifunctional additive used.

Fourth, the reaction product resulting from the reaction of a mixturecomprising (1) a polyester prepared from bifunctional ingredientsincluding at least one dibasic carboxylic acid containing at least threecarbon atoms and at least one glycol, said polyester having a hydroxylnumber between 40 and (a preferred range is from 50 to 60) and an acidnumber from 0 to 7; (2) at least one bifunctional additive selected fromthe group consisting of diamines, amino alcohols, dicarboxylic acids,amino carboxylic acids, hydroxy carboxylic acids and the ureas,guanidines and thioureas containing a primary amino group, saidbifunctional additive being used in an amount such that the total numberof NH2 and :COOH equivalents present in such bifunctional reactant shallbe from 0.06 to 0.48 equivalent per mol of polyester, and (3) at leastone diisocyanate selected from the group consisting of 4,4-diphenyldiisocyanate; 4,4'-diphenylene methane diisocyanate; 4,4'-tolidinediisocyanate; dianisidine diisocyanate; 1,5-naphthalene diisocyanate;4,4'-diphenyl ether diisocyanate; and p-phenylene diisocyanate, thediisocyanate being used in an amount equal to the sum of from 0.70 molto 0.99 (a preferred range is from 0.90 to 0.99) mol of diisocyanate permol of polyester plus the molar amount of diisocyanate equivalent to themols of bifunctional additive used.

Listed below are the reactants used to form some preferred polyestersand polyesteramides which, when prepared and subsequently modified by adiisocyanate and, optionally, a bifunctional additive in accordance withthe appropriate limitations indicated in the description of the fourtypes of synthetic elastomers, will produce elastomeric products.

. Ethylene glycol plus adipic acid.

. Propylene glycol 1,2 plus adipic acid.

. Ethylene glycol (80 mol propylene glycol 1,2

(20 mol percent) plus adipic acid.

. Ethylene glycol (80 mol percent), propylene glycol,

(20 mol percent) plus azelaic acid.

. Ethylene glycol (80 mol percent), propylene glycol,

1,2 (20 mol percent) plus sebacic acid.

. Ethylene glycol (80 mol percent), propylene glycol 1,2 (20 molpercent) plus dilinoleic acid (20 mol percent), adipic acid (80 molpercent).

7. Ethylene glycol (80 mol percent), glycerine monoethyl ether (20 molpercent) plus adipic acid.

8. Ethylene glycol (80 mol percent), butylene glycol 1,4 (20 molpercent) plus adipic acid.

9. Ethylene glycol (80 mol percent), propylene glycol 1,3 (20 molpercent) plus adipic acid.

Ethylene glycol (80 mol percent), pentane diol 1,5

(20 mol percent) plus adipic acid.

Ethylene glycol (80 mol percent), glycerine monoisopropyl ether (20 molpercent) plus adipic acid.

Ethylene glycol (80 mol percent), propylene glycol l, 2 (from 18 to 5mol percent), ethanol amine (from 2 to 15 mol percent), plus adipicacid.

Ethylene glycol (80 mol percent), propylene glycol 1., 2 (20 molpercent) plus maleic acid (from 3 to 6 mol percent), adipic acid (from97 to 94 mol percent).

Ethylene glycol (80 mol percent), propylene glycol l, 2 (from 19 to 17mol percent), piperazine (from 1 to 3 mol percent) plus adipic acid.

Ethylene glycol (80 mol percent), propylene glycol 1,2 (from 18 to 5 molpercent), dihydroxyethyl aniline (fro m2 to 15 mol percent) plus adipicacid.

Ethylene glycol (80 mol percent), diethylene glycol (20 mol percent)plus adipic acid.

Ethylene glycol (from 90 to mol percent), propylene glycol 1,2 (from 10to 90 mol percent) plus adipic acid.

Ethylene glycol (from 90 to 10 mol percent), propylene glycol 1,2 (from10 to 90 mol percent) plus azelaic acid.

form of one of its dimers such as the dimer of 2,4-tolylene diisocyanateof the following formula:

Each sage...

G N00 N00 The dimer is less toxic than the monomeric material.

Of the first class of elastomeric polymers described above, those ofparticular interest are the rubber-like polymers resulting frompolyethylene adipate modified by 4,4- diphenyl diisocyanate;1,5-naphthalene diisocyanate; 4,4- diphenyiene methane diisocyanate, ormixtures thereof: polypropylene. 1,2 adipate modified by 4,4-diphenyldiisocyanate; 1,5-naphthalene diisocyanate; 4,4-diphenylene methanediisocyanate, or mixtures thereof; polyethylene (80 mol percent)propylene 1,2 (20 mol percent) adipate modified by 4,4-diphenyldiisocyanate; 1,5-naphthalene diisocyanate; 4,4'-diphenyl methanediisocyanate, or mixtures thereof; polyethylene (80 mol percent)propylene 1,2 (20 mol percent) azelate modified by 4,4-diphenyldiisocyanate; 1,5 -naphthalene diisocyanate; 4,4'-diphenylene 6 methanediisocyanate, or mixtures thereof; and polyethylene mol percent)propylene 1,2 (from 19 to 17 mol percent) piperazine (from 1 to 3 molpercent) adipate modified by 4,4'-diphenyl diisocyanate; 1,5-naphthalenediisocyanate; 4,4-diphenylene methane diisocyana.e, or mixtures thereof.These polymers, when cured, have been found to possess outstandingphysical properties.

Of the second class of elastomeric polymers described above, those ofparticular interest are the rubber-like polymers resulting frompolyethylene adipate modified by a meta tolylene diisocyanate;polypropylene 1,2 adipate modified by a meta-tolylene diisocyanate;polyethylene (80 mol percent) propylene 1,2 (20 mol percent) adipatemodified by a meta-tolylene diisocyanate; polyethylene (80 mol percent)propylene 1,2 (20 mol percent) azelate modified by a meta-tolylenediisocyanate; and polyethylene (80 mol percent) propylene 1,2 (from 19to 17 mol percent) piperazine (from 1 to 3 mol percent) adipate moditiedby a meta-tolylene diisocyanate. Mixtures of meta tolylene diisocyanatessuch as mixtures of 2,4- and 2,6- tolylene diisocyanates may also beused.

Of the third class of elastomeric interpolymers described above, thoseof particular interest are the rubberlike materials resulting from (1)Polyethylene adipate modified by a meta-tolylene diisocyanate and byethylene diamine, tetramethylene diamine, hexamethylene diamine, ethanolamine, benzidine; 4,4-diamino diphenyl methane or mixtures thereof.

(2) Polypropylene 1,2-adipate modified by a metatolylene diisocyanateand by ethylene diamine, tretramethylene diamine, hexamethylene diamine,ethanol amine, benzidine; 4,4-diamino diphenyl methane or mixturesthereof.

(3) Polyethylene (80 mol percent) propylene 1,2 (20 mol percent) adipatemodified by a meta-tolylene di isocyanate and by ethylene diamine,tetramethylene diamine, hexamethylene diamine, ethanol amine, benzidine;4,4-diarnino diphenyl methane or mixtures thereof.

(4) Polyethylene (80 mol percent) propylene 1,2 (20 mol percent) azelatemodified by a meta-tolylene and by ethylene diamine, tetrarnethylenediamine, hexamethylene diamine, ethanol amine, benzidine; 4,4'-diaminodiphenyl methane or mixtures thereof.

Mixtures of meta-tolylene diisocyanates such as mixtures of 2,4- and2,6-tolylene diisocyanate may also be used.

Of the fourth class of elastomeric interpolymers described above, thoseof particular interest are the rubberlike materials resulting from (1)Polyethylene adipate modified by 4,4-diphenyl diisocyanate; 1,5-naphthalene diisocyanate; 4,4'-diphenylene methane diisocyanate, ormixtures thereof, and by ethylene diamine, tetramethylene diamine,hexamethylene diamine, ethanol amine, benzidine, 4,4-diamino diphenylmethane or mixtures thereof.

(2) Polypropylene 1,2 adipate modified. by 4,4-diphenyl diisocyanate;1,5-naphthalene diisocyanate; 4,4- diphenylene methane diisocyanate, ormixtures thereof, and by ethylene diamine, tetramethylene diamine,hexarnethylene diamine, ethanol amine, benzidine, 4,4-diamino diphenylmethane or mixtures thereof.

(3) Polyethylene (SOmol percent) propylene 1,2 (20 mol percent) adipatemodified by 4,4'-diphenyl diisocyanate; 1,5-naphthalene diisocyanate;4,4-diphenylene methane diisocyanate, or mixtures thereof, and byethylene diamine, tretramethylene diamine, hexamethylene diamine,ethanol amine, benzidine, 4,4-diamino diphenyl methane or mixturesthereof.

(4) Polyethylene (80 mol percent) propylene 1,2 (20 mol percent) azelatemodified by 4,4-diphenyl diisocyanate; l,5-naphthalene diisocyanate;4,4'-diphenylene methane diisocyanate, or mixtures thereof, and byethylene diamine, tetramethylene diamine, hexamethylene di- Examplel.-Pr eparazion of a typical polyester Adipic acid (3515 parts) wasplaced in a liter, 3- necked flask fitted with a stirrer, thermo-couplewell, gas inlet tube, distilling head, and condenser. To the acid wereadded 1064 parts of ethylene glycol and 869 parts of propylene 1,2glycol. The molar ratio of dibasic acid to glycol is 1:1.19. The mixturewas heated to l30160 C. until most of the water had distilled oil. Thetemperature was then gradually raised to 200 C., the pressure beinggradually reduced to mm. and nitrogen being bubbled through the melt.After 23 /2 hours a soft white Waxy solid was obtained. Determinationsshowed the acid number to be 3.5 and the hydroxyl number to be 58.6.

Example 2.Preparation of the diisocyanate-modifietl polymer A quantityof polyester was prepared from adipic acid, ethylene glycol, andpropylene 1,2 glycol according to the general method and insubstantially the same ratios as shown in Example 1. This polyester hadan acid number of 3.1 and a hydroxyl number of 55.6. After heating 2270parts of this polyester in a steam-heated Baker-Perkins mixer to 120 C.,4,4-diphenyl diisocyanate (280.3 parts of 95.7% purity or 0.96 mol permol of polyester) was added. After ten minutes of mixing the hot meltwas poured into a carnauba wax coated tray and baked for 8 hours at 130C. The resulting polymer had excellent processing characteristics on arubber mill. Tests showed the following physical properties-intrinsicviscosity 1.69, percent gel 3.9, plastic flow (1500 p. s. i.--212 F.) 85seconds per inch, and softening point 186 C.

Example 3.Preparation of the diisocyanate-modified polymer A quantity ofpolyester was prepared from adipic acid, ethylene glycol, and propylene,1,2 glycol according to the general method and in substantially the sameratios as shown in Example 1. This polyester had an acid number of 3.1and a hydroxyl number of 55.6. After heating 200 parts of this polyesterto 120 C. in an iron kettle, 2,4- tolylene diisocyanate (20.11 parts of99.7% purity or 1.10 mols of diisocyanate per mol of polyester) wasadded. After 15 minutes of mixing, the material was poured into a waxedaluminum tray and baked for 8 hours at 120 C. The resulting polymer hadexcellent processing characteristics on a rubber mill.

Example 4.-Preparation of modified interpolymer The polyester (2270parts) prepared according to Example 1 was placed in a steam-heatedBaker-Perkins mixer, melted, and heated to 120 C. To this was added 0.12mol of hexamethylene diamine per mol of polyester and 1.07 mols of4,4'-diphenyl diisocyanate per mol of polyester. After ten minutes ofmixing, the hot melt was poured into a carnauba wax coated tray andbaked for 8 hours at 130 C. The resulting interpolymer had excellentprocessing characteristics on a rubber mill.

Example 5 This interpolymer was prepared in the same manner as Example 4except adipic acid was used as a molar replacement for the hexamethylenediamine. This product, too, had good processing characteristics on arubber mill.

Example 6 This interpolymer was prepared in the same manner as Example 4except ethanolamine was used as a molar replacement forhexamethylenediamine. The processing characteristics of the materialwere. good.

Example 7 mol of polyester were used. The reacted material possessedexcellent processing characteristics on a rubber mill.

In the curing of the processible elastomers, any organic diisocyanate,polyisocyanate or mixtures of di'isocyanates, of polyisocyanates, or ofboth may be used. It is necessary to control the amount ofpolyisocyanate added to elfect a cure. The use of too small an amount ofpolyisocyanate produces an under-cured product. The use of too muchpolyisocyanate is a waste of material with no improved properties in thecured product and in some cases produces a cured polymer more resinousthan rubber-like. Thus, without the use of magnesium oxide, it isnecessary, when curing the polymers of the first and second classes, toadd enough polyisocyanate to the polymer so that the total number of NCOequivalents, including that added in the formation of the uncuredpolymer, shall be from 2.80 to 3.20 equivalents per mol of polyester orpolyesteramide. When curing the polymers of the third and fourthclasses, an additional amount of -NCO, equivalent to twice the molaramount of bifunctional additive used in preparing the interpolymer, isrequired.

With the use of magnesium oxide, it is possible to reduce the amount ofpolyisocyanate required to effect a cure to from 2.40 to 2.80equivalents per mol of polyester or polyesteramide. This reduction ofpolyisocyanate results in a lower cost for the cured elastomer withoutmaterially detracting from its physical properties.

To illustrate the effect of magnesium oxide and reduced amounts ofisocyanate on the cured properties of the resulting polymers, thefollowing compounds were prepared. Parts shown are by weight.

Recipe 1 2 3 4 Uncured polymer 100.00 100.00 100.00 100.00 Diisocyanate4. 0 4. 00 4. 0O Magnesium Oxide 2. (10 2.00 4. 00

TABLE I Recipe 1 2 3 4 N00 equivalents 2. 56 1. 88 2. 56 2. 56 Tensilestrength 2, 000 875 3, 000 3, 200 Elongation 810 930 870 870 700%Modulus 1, 350 200 1, 725 2, 000 500% Modulus 500 675 900 300% Modulus200 125 275 350 The tensile strength is expressed in pounds per squareinch. The elongation is expressed in percent stretch at break. Themodulus represents the pounds per square inch required to elongate thetest specimen the percentage indicated.

An analysis of the test results shown in Table I will indicate that itis possible to develop superior physical properties in the curedpolymers by the use of magnesium oxide even though the number of NCOequivalents is less than 2.80 per mol of polyester instead of the 2.80to 3.20 which is required when no magnesium oxide is present. It will beseen that recipe 1, which contains NCO equivalents in the amount of2.56, de-

veloped a tensile strength of 2000 pounds per square inch. By theaddition of 4 parts by weight of magnesium oxide (see recipe 4), it waspossible to improve the tensile to 3200 pounds per square inch. Asimilar improvement was obtained in recipe 3 where 2 parts of magnesiumoxide were used.

Since the polyisocyanate is the most expensive ingredient of thepolymer, any substantial reduction in the amount thereof used in formingthe cured polymer without accompanying reduction of strength or otherphysical properties is of prime importance.

This application is a continuation-in-part of my copending applicationSerial Number 263,702, filed December 27, 1951, now abandoned.

While certain representative embodiments and details have been shown forthe purpose of illustrating the invention, it will be apparent to thoseskilled in this art that various changes and modifications may be madetherein without departing from the spirit or scope of the invention.

What is claimed is:

1. A composition of matter comprising from 0.50 to 20 parts by Weight ofmagnesium oxide and 100 parts by weight of an elastomericisocyanate-modified linear polyester selected from the group consistingof (A) the reaction product resulting from the reaction 'of a mixturecomprising (1) a material prepared from biiunctional ingredientsincluding at least one dibasic carboxylic acid and at least onecomplementary bifunctional reactant in which the functional groups areselected from the class consisting of the hydroxyl group and thehydrogen-bearing amino groups, the hydrogen-bearing amino groups beingpresent in an amount not to exceed 7.5% of the total functional groupsof said complementary bifunctional reactant, said material having ahydroxyl number from 40 to 100 and an acid number from to 7, and (2) atleast one diisocyanate selected from the group consisting of4,4-diphenyl diisocyanate; 4,4'diphenylene methane diisocyanate;dianisidine diisocyanate; 4,4-t-olidine diisocyanate; 1,5-naphthalenediisocyanate; 4,4'-diphenyl ether diisocyanate, and p-phenylenediisocyanate, the diisocyanate being used in an amount ranging from 0.70to 0.99 mol per mol of said material; (B) the reaction product resultingfrom the reaction of a mixture comprising (3) a material prepared frombifunctional ingredients including at least one dibasic carboxylic acidand at least one complementary bifunctional reactant in which thefunctional groups are selected from the class consisting of the hydroxylgroup and the hydrogen-bearing amino groups, the hydrogen-bearing groupsbeing present in an amount not to exceed 30% of the total functionalgroups of said complementary bifunctional reactant, said material havinga hydroxyl number from 30 to 140 and an acid number from 0 to 12, and(4) at least one tolylene diisocyanate used in an amount ranging from0.85 to 1.10 mols per mol of said material; (C) the reaction productresulting from the reaction of a mixture comprising (5) a polyesterprepared from bifunctional ingredients including at least one dibasiccarboxylic acid containing at least three carbon atoms, and at least oneglycol, said polyester having an hydroxyl number from 30 to 140 and anacid number from 0 to 12, (6) at least one bifuncti onal additiveselected from the group consisting of diamines, amino alcohols,dicarboxylic acids, amino carboxylic acids, hydroxy carboxylic acids andthe ureas, guanidines, and thioureas containing a primary amino group,said bifunctional additive being used in an amount such that the totalnumber of NH2 and -COOH equivalents present in said bifunctionalreactant shall be from 0.06 to 0.24 equivalent per mol of polyester, and(7) at least one tolylene diisocyanate used in an amount equal to thesum of from 0.85 mol to 1.10 mols of diisocyanate per mol of polyesterplus the molar amount of diisocyanate equivalent to the mols of saidbifunctional additive used; (D) the reaction product resulting from thereaction of a mixture comprising (8) a polyester prepared frombifunctional ingredients including at least one dibasic carboxylic acidcontaining at least three carbon atoms and at least one glycol, saidpolyester having a hydroxyl number between 40 and and an acid numberfrom 0 to 7, (9) at least one bifunctional additive selected from thegroup consisting of diamines, amino alcohol, dicarboxylic acids, aminocarboxylic acids, hydroxy carb'oxylic acids, and the ureas, guanidinesand thioureas containing a primary amino group, said bifunctionaladditive being used in an amount such that the total number of -NH2 and-COOH equivalents present in said bifunctional reactant shall be from0.06 to 0.48 equivalent per mol of polyester, and (10) at least onediisocyanate selected from the group consisting of 4,4-diphenyldiisocyanate; 4,4'-diphenylene methane diisocyanate; 4,4-to1idinediisocyanate; dianisidine diisocyanate; 1,5-naphthalene diisocyanate;4,4-diphenyl ether diisocyanate, and p-phenylene diisocyanate, thediisocyanate being used in an amount equal to the sum of from 0.70 molto 0.99 mol of diisocyanate per mol of polyester plus the molar amountof diisocyanate equivalent to the mols of bifunctional additiveused--(A) and (B) being reacted With a suflicient amount of at least onepolyisocyanate to bring the total number of NCO equivalents present insaid composition to from 2.40 to 2.80 equivalents per mol of saidmaterial and (C) and (1)) being reacted with a sufficient amount of atleast one polyisocyanate to bring the total number of --NCO equivalentspresent in said composition to the sum of from 2.40 to 2.80 equivalentsper mol of said polyester plus twice the molar amount of bifunctionaladditive used in the preparation of said elastomeric reaction product.

2. A composition of matter comprising (1) from 0.50 to 20 parts byweight of magnesium oxide, (2) 100 parts by weight of an elastomericisocyanate-modified linear polyester resulting from the reaction of amixture comprising (A) a polyester prepared from at least one dibasiccarboxylic acid and at least one glycol, said polyester having ahydroxyl number from 40 to 100 and an acid number from 0 to 7 and (B)4,4-diphenyl diisocyanate used in an amount ranging from 0.90 to 0.99mol per mol of said polyester and (3) a sufiicient amount of at leastone polyisocyanate to bring the total number of -NCO equivalents presentin said composition to from 2.40 to 2.80 equivalents per mol of saidpolyester.

3. A composition of matter comprising (1) from 0.50

to 20 parts by weight of magnesium oxide, (2) 100 parts by weight of anelastomeric isocyanatemodified linear polyester resulting from thereaction of a mixture comprising (A) a polyester prepared from at leastone dibasic carboxylic acid and at least one glycol, said polyesterhaving a hydroxyl number from 30 to and an acid number from 0 to 12 and(B) tolylene diisocyanate used in an amount ranging from 0.90 to 1.00mol per mol of said polyester and (3) a sufiicient amount of at leastone polyisocyanate to bring the total number of NCO equivalents presentin said composition to from 2.40 to 2.80 equivalents per mol of saidpolyester.

4. A composition of matter comprising (1) from 0.50 to 20 parts byweight of magnesium oxide, (2) 100 parts by weight of an elastomericisocyanate-modified linear polyester resulting from the reaction of amixture comprising (A) a polyester prepared from at least one dibasiccarboxylic acid containing at least three carbon atoms and at least oneglycol, said polyester having a hydroxyl number from 30 to 140 and anacid number from 0 to 12 (B) a diamine used in an amount such that thetotal number of NH2 equivalents is from 0.06 to 0.24 equivalent per molof polyester and (C) tolylene diisocyanate used in an amount equal tothe sum of from 0.90 to 1.00 mol per mol of polyester plus the molaramount of diisocyanate equivalent to the mols of diamine used and (3) asufiicient amount of at least one polyisocyanate to bring the totalnumber of -NCO equivalents present in said composition to the sum offrom 2.40 to 2.80 equivalents per mol of said polyester plus twice themolar amount of diamine used in the preparation of said elastomericreaction product.

5. A composition of matter comprising 1) from 0.50 to 20 parts by Weightof magnesium oxide, (2) 100 parts by Weight of an elastomericisocyanate-modified linear polyester resulting from the reaction of amixture comprising (A) a polyester prepared from at least one dibasiccarboxylic acid containing at least three carbon atoms and at least oneglycol, said polyester having a hydroxyl number from 40 to 100 and anacid number from to 7 (B) a diamine used in an amount such that thetotal number of NH2 equivalents is from 0.06 to 0.48 equivalent per molof polyester and (C) 4,4-diphenyl diisocyanate used in an amount equalto the sum of from 0.90 to 0.99 mol per mol of polyester plus the molaramount of diisocyanate equavalent to the mols of diamine used and 3) asufficient amount of at least one polyisocyanate to bring the totalnumber of NCO equivalents present in said composition to the sum of from2.40 to 2.80 equivalents per mol of said polyester plus twice the molaramount of diamine used in the preparation of said elastomeric reactionproduct.

6. A composition of matter comprising (1) from 0.50 to 20 parts byWeight of magnesium oxide, (2) 100 parts by Weight of an elastornericisocyanate-modified linear polyester resulting from the reaction of amixture comprising (A) a polyester prepared from at least one dibasiccarboxylic acid containing at least three carbon atoms and at least oneglycol, said polyester having a hydroxyl number from to and an acidnumber from 0 to 7 (B) a diamine used in an amount such that the totalnumber of NH2 equivalents shall be from 0.06 to 0.48 equivalent per molof polyester and (C) 4,4-tolidine diisocyanate used in an amount equalto the sum of from 0.90 to 0.99 mol per mol of polyester plus the molaramount of diisocyanate equivalent to the mols of diamine used and (3) asuificient amount of at least one polyisocyanate to bring the totalnumber of -NCO equivalents present in said composition to the sum offrom 2.40 to 2.80 equivalents per mol of said polyester plus twice themolar amount of diamine used in the preparation of said elastomericreaction product.

Bayer et al.: Rubber Chem. and Tech., October-December 1950, pages812835.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.2,798,859 July 9, 1957 William L. Bruce ror appears in the printedSpecification It is hereby certified that er ing correction and that thesaid LGtGBrB of the above numbered patent requir Patent should read ascorrected below.

l, for "(H0-" read HO- column 6,

' line 66, for "4,4-diphenylene" read 4,4-

C'oltmms l and 2, equation (5) extreme left-hand portion thereof, linelines 31 and 32, for "tretramethylene" read tetramethylene line 18, for"equavalent" read equivalent diphenylene column 11,

Signed and sealed this 10th day of September 1957.

Attest:

Atte'ating Officer Cunnissioncr of Patents

2. A COMPSITION OF MATTER COMPRISING (1) FROM 0.50 TO 20 PARTS BY WEIGHTOF MAGNESIUM OXIDE, (2) 100 PARTS BY WEIGHT OF AN ELASTOMERICISOCYANATE-MODIFIED LINEAR POLYESTER RESULTING FROM THE REACTION OF AMIXTURE COMPRISING (A) A POLYESTER PREPARED FROM AT LEAST ONE DIBASICCARBOXYLIC ACID AND AT LEAST ONE GLYCOL, SAID POLYESTER HAVING AHYDROXYL NUMBER FROM 40 TO 100 AND AN ACID NUMBER FROM 0 TO 7 AND (B)4,4''-DIPHENYL DIISO CYANATE USED IN AN AMOUNT RANGING FROM 0.90 TO 0.99MOL PER MOL OF SAID POLYESTER AND (3) A SUFFICIENT AMOUNT OF AT LEASTONE POLYISOCYANTE TO BRING THE TOTAL NUMBER OF -NCO EQUIVALENTS PRESENTIN SAID COMPOSITION TO FROM 2.40 TO 2.80 EQUIVALENTS PER MOL OF SAIDPOLYESTER.